抄録
Following the same experiment conducted by the writer in 1947, the effect of varied date of initial feeding on fish fry was examined on the growth rate and the color change of “wakin” gold-fish, Carassius auratus in 1949 and 1950. The fish specimens, the same brood of fry hatched out on the same day, were kept in 4 (1950) and 5 (1949) lots under the probable equivalent condition in each year ;they were fed by Moina sp.and some prepared food in an excess amount daily (Table 1). In the experiment of 1950 the volume of water carrying each lot of fish was differed proportionally to the number of fish. The result of the checking of reared fish was shown in Tables 2 and 3.
It was found clearly that the differential growth of fish among the lots of each year showed nearly corresponding rate to the varied date of the first feeding, whether in total weight of the lot, growth of individuals and the survival rate of the group.The best growth as far as the total weight concerned of fish, as expected, was found in the lot whose feeding started on the day of their hatching. The change of coloration from larval dark color to the colorless or reddish phase of gold-fish was not apparently reflected by the date of initial feeding.